Challenge: Employee Class using Instance & Class Variables

Objective: Create an Employee class that uses both instance variables and a class variable.

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1. Class Properties (Variables)

• Instance Variables: (Unique to each employee object)
  • name
  • salary
  • designation
  • employee_id (Automatically assigned, not taken as a parameter)
• Class Variable: (Shared across all employee objects)
  • employee_count
  • Initial Value: 101
  • Purpose: Used to automatically generate the next employee ID.

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2. Employee ID Rules

• The first employee ID should be E101.
• The next should be E102, and so on.
• The ID must be assigned automatically when a new employee object is created.
• The employee_count class variable must be incremented after assigning an ID.

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3. Class Methods (Functions)

• __init__(self, name, salary, designation)
  • Takes name, salary, and designation as parameters.
  • Does NOT take employee_id as a parameter.
  • Inside this function:
    • Assigns an employee_id using the current employee_count (e.g., “E101”).
    • Increments the employee_count class variable for the next employee.
• show_details(self)
  • Prints all the details of the employee: Name, Salary, Employee ID, and Designation.
• total_employees(cls) (A Class Method)
  • Correction: This must be a class method, not a static method.
  • Purpose: Returns the total number of employees created.
  • Logic: Calculate total employees as employee_count - 101.

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4. Key Summary

• Use a class variable (employee_count) to auto-generate IDs.
• Use instance variables to store individual employee details.
• Implement three methods: __init__, show_details, and the class method total_employees.

class Employee:

    employee_count = 101

    def __init__(self, name, desig, sal):
        self.name = name
        self.designation = desig
        self.salary = sal
        self.eid = 'e' + str(Employee.employee_count)
        Employee.employee_count += 1

    def show_details(self):
        print('Name:',self.name)
        print('Eid:',self.eid)
        print('Designation:',self.designation)
        print('Salary:',self.salary)

    @classmethod
    def total_emp(cls):
        return cls.employee_count - 101


e1 = Employee('John', 'Manager', 10000)
e2 = Employee('Mark', 'Team Leader', 8000)

e1.show_details()
print('')
e2.show_details()
print('Total Employees:', e1.total_emp())